Device for adjusting dental illumination

ABSTRACT

A device is used for adjusting dental lights, wherein the light, with present focusing, must be placed according to location of and distance from a variable treating place with the use of an electric steering device. The invention is particularly characterized in that a device is provided at the location of the treating place, for example, a dental treating chair, which copies the changes in position and transmits them to a steering device.

United States Patent [191 [111 33 9 Hetz June 18, 1974 DEVICE FOR ADJUSTING DENTAL 2,223,182 1271322 geibejrfi 54371021.):

, ILLUMINATION ,28 ,55 1 ran e 3,375,362 3/1968 Klippert 240/l.4 [75] Inventor: Walter Hetz, Erlangen, Germany [73] Assignee: Siemens Aktiengesellschaft, Primary Examiner Richai-d MoSes Erlangen, Germany Attorney, Agent, or Firm-Richards & Geier [22] Filed: May 8, 1972 [21] Appl. No.: 251,090 [57] ABSTRACT C 3 us g s M h 4 A device is used for adjusting dental lights, wherein g 'g o the light, with present focusing, must be placed acan one cording to location of and distance from a variable treating place with the use of an electric steering dei 240/4115 240/ vice. The invention is particularly characterized in 58 d 15 1 4 61 that a device is provided at the location of the treating 1 0 arc place, for example, a dental treating chair, which copies the changes in position and transmits them to a [56] References Cited Steering device.

UNITED STATES PATENTS 1,469,928 10/1923 Lazar 240/61 X 9 Claims, 6 Drawing Figures PATENTEUJUN 1 8 I914 3,818.2 1 7 SHEET 2 [1F 3 PAIEMEB JUN rs m4 SHEET 3 BF 3 l llllll ll lllllllllllll l| DEVICE FOR ADJUSTING DENTAL ILLUMINATION The present application is a continuation-in-part of my copending US. Pat. application filed Mar. 4, 1970, Ser. No. 16,365 now abandoned.

This invention relates to a device for adjusting dental lights, wherein the light, with preset focusing, must be set in the best possible way relatively to a varying treating place depending upon its location and distance, an electrical steering device being used for that purpose.

At this time dental lights must be set by hand depending upon the position of the patent and the location of the treating place, as well as the size of the patient. Sometimes an adjustment is necessary even during the treatment, such adjustment already for hygienic reasons requires an automatic adjustment which should be carried out without touching the light by hand.

A known actuating device uses means with photocells, wherein a pilot lamp coupled with the main light acts upon a plurality of photocells located close to the treating area, for example, the head rest, the arrangement being such that the main light is always directed to the treating area. This subsequent actuation of the main light can be carried out by electric motor in a known manner. This prior art actuating device requires a comparatively large expense and yet produces only an approximate adjustment, where, on the one hand, the location of the treating area can deviate from the location of the photocells and, on the other hand, this adjustment cannot take into consideration the different setting of the light when treating upper and lower jaws.

An object of the present invention is to provide an operating device of the described type wherein the subsequent adjustment of the main light to the treating area can be carried out effectively by comparatively simple means.

Other objects of the present invention will become apparent in the course of the following specification.

In' the accomplishment of the objectives of the present invention it was found desirable to provide a device close to the treating place, such as the dental treating chair, which copies its change in position and transmits it to a steering device for the main light. This device is preferably a mechanical unit which automatically covers at least the seat height and the inclination of the back support relatively to the seat; this information is transmitted by suitable means, such as resistance or inductive members to elements setting the main light, for example, electric motors. To take into consideration the different sizes of patients it is advisable to provide additionally a mechanically operable adjuster which operates in the plane of the chair back and which affects the angle setter for the main light.

The invention will appear more clearly from the following detailed description when taken in connection with the accompanying drawings showing by way of example only, a preferred embodiment of the inventive idea.

In the drawings:

FIG. 1 is a side view of the device of the present invention including a dental treating chair and dental lights.

FIG. 2 is similar to FIG. 1 but shows the chair in a different position.

FIG 3 is a transverse section along the line IIIIII of FIG. 2 on an enlarged scale.

FIG. 4 is a longitudinal section along the line IV-IV of FIG. 3.

FIG. 5 is a section on an enlarged scale of the required value producing means of FIGS. 1 and 2.

FIG. 6 is a circuit diagram of the adjusting device.

FIG. 1 is a simplified view of a dental treating location having a treating chair 1 and a movable dental illuminating device 2. The chair 1 consists essentially of a base 3, a seat 4 which is adjustable in height relatively to the base, back support 5 swingably connected to the seat and an arm support 6. A head pillow 7 lies loosely upon the back 5 for supporting the head of the patient. The illuminating device 2 is a so-called twin light; it includes a supporting arm 8 and two lights 9 and 10 located upon the ends of the arm and emitting light ray bundles which can be directed to the head portion of the chair upon which lies the head of the patient. Thus the light spot is directed to the mouth of the patient. The supporting arm 8 is swingably mounted upon a carriage 11 which is movable upon two rails 12 and 13 in the direction of the arrows. Due to this arrangement the direction of the light rays of the illuminating device can be changed when the position of the chair and thus the location of patients mouth are changed. The swinging axle of the arm 8 is indicated at 14. For better visualization the rail 13 and a part of the carriage 11 are shown as broken ofi within the range of the illuminating device. The carriage 11 and the arm 8 are driven by motors. The rails 12 and 13 are fixed by carriers 15 and 16 to the roof 17 of the treating chamber.

Details of the support and guiding of the carriage 11 and of the arm 8, as well as the arrangement of the operating motors are shown in FIGS. 3 and 4.

The carriage 11 is guided by rollers 20 and 21 in the U-shaped rails 12 and 13. Within the casing of the carriage 11 there is a motor 22 for operating the carriage and a motor 23 for swinging the arm 8. When the arm 8 is being swung force is transmitted through a gear 24 carried by the swinging axle 14 of the arm 8. For moving the carriage l1 longitudinally a pinion 25 is used which when rotated moves over the toothed rack 26 fixed in the rail 13.

A resistance member 27 is mounted in the left hand J rail 12 and extends along its length; a slider 28 fixed to the casing of the carriage 11 is pressed by a spring against it. The carriage 11 carries another resistance member 29 having the shape of a ring segment and co operating with a slider 30'the contact point of which lies under spring pressure against the resistance path 29. The slider 30 is isolatably fixed on the axle 14. This resistance segment is shown in side view in FIG. 4. Screw terminals 31, 32 and 33 are clamped to the individual conduits of the contacts of resistances 27 and 29. The two resistance lengths 27 and 29 constitute the actual value indicator for the illuminating device 2.

The illuminating device in the illustrated twinarrangement has the great advantage that in case of a lying patient upper as well as lower jaw treatments can be carried out with the same light setting. As a rule the two lights 9 and 10 need to be set only once in their relative positions to provide the best possible setting of the light spot desired at the treating location.

As already stated, the swinging of the arm 8 about the axis 14 and the movement of the carriage 11 along the rails 12 and 13 are carried out by the two electric motors 22 and 23 no. 3). As indicated in FIGS. 1 and 2, when the positions of the chair, such as set height and inclination of the back, are changed, the locations of the carriage 11 and the arm 8 with the lights 9 and 10 are also changed. When the back of the chair is straightened from an angle B, to an angle the carriage is moved to the left and at the same time the angle of the arm is changed from a, to a Then the distance of the lights 9 and from the treating location, namely the mouth of the patient, remains substantially the same. The lights 9 and 10 form along with the treating location the angles of an isosceles triangle.

To the side of the treating chair there is a control device 40. It consists essentially of a casing 41 connected to the linkage of the chair back with the chair seat, a rod 42 variable in its length and extending to the floor, and a part 43 fixed to the chair back and constituting a part of a setting device 43, 57 which is also adjustable in its length. The telescopic rod 42 is used to fix the height of the seat 2 while the setting device 43, 57 fixes the inclination of the chair back 5. In addition the member 43 can be used to take into consideration different locations of the treated part (mouth of the patient) in case of patients of different sizes (fine setting). The described control device is the mechanical part of the real value indicator of the adjusting device. This indicator also has an electrical part consisting essentially of two lengths of resistances 51 and 60 with corresponding connections and attachments. Details and operation appear on FIG. 5 while the circuit is shown in FIG. 6.

The telescopic rod 42 used for setting the height of the seat of the chair consists of a guiding tube 44 which is connected with a liquid containing cylinder 45 provided in the casing 41, and a rod 46 movable axially in the tube 44 and carrying a piston. One end of the telescopic rod 42, namely the point of the rod 46, lies upon the floor of the treating chamber (FIGS. 1 and 2), while the other end is connected by the casing 41 with the part of the chair adjustable in height. The piston rod 48 serves to move the rod 46 relatively to the resistance 51. A piston 47 is located in the cylinder 45 and has a piston rod 48 guided through the cover 49 of the cylinder 4S. If the seat 4 (FIG. 2) of the chair is lowered, then the rod 46 pushes the liquid out of the tube 44 into the cylinder 45 and raises the piston 47. A guide rod 50 is angularly firmly connected with the piston rod 48. As shown in FIG. 5, a length of resistance 51 is fixed along the rod 50 by suitably isolated holders 52 and 53. A guide 54 is mounted upon the rod 50 and is longitudinally movable thereon. An insulated slider 55 is connected with the guide 54 and has a contact point lying upon the resistance 51. The individual connections of the ends of the resistance 51 and of the slider 55 are shown in the circuit of FIG. 6. The slider 55 is similar in construction to the slider 28 shown in FIG. 3. The guide 54 consists of a sleeve slidably mounted upon the rod 50.

A rod 56 is pivotally connected to the guide 54. The other end of the rod 56 is pivotally connected with the part 43 which can be pulled out of the rod 57 of the setting combination 43, 57. The rod 57 is pivotally connected at 58 to the casing 41. A guide member 59 is firmly connected to the rod 56 and carries a slider fixed thereon, the contact point of which lies upon a resistance segment 60 insulatably connected with the guide 54. The resistances 51 and 60 in the casing 41 of the device 40 correspond as far as their resistance values are concerned to those of the resistances 27 and 29 located in carriages '11 and 12.

The location of the guide 59 shown in FIG. 5 corresponds to an angular location of the setting device 43, 57 which corresponds to the location of the head of a comparatively small patient sitting upon the chair. In case of a larger patient the part 43 of the setting device 43, 57 is pulled so far toward the head end of the back of the chair until the light bundle of the double lights is directed upon the mouth of the patient. This adjustment is carried out manually by the doctor or his assistant as soon as the patient has been seated in the chair. By pulling the part 43 in the direction of the head end of the chair back, the guide 54 with the slider 55 are moved somewhat to the left; the angle 5, remains fixed while the angle a, is diminished. The resistance change in the two resistances 51 and 60 results, according to the circuit shown in FIG. 6, in that the motors 22 and 23 in the carriage 11 (FIG. 1) are switched on in the corresponding direction of rotation.

If the chair back 5 is moved from a strongly inclined position (FIG. 1) to an upright position (FIG. 2), then the setting device 43, 57 is also raised due to its connection with the back 5. Then the angle B, is changed to B as indicated by broken lines in FIG. 5. When the setting device 43, 57 is raised the guide 54 is also moved along the rod 50. Due to the coupling of the guide 54 with the resistance 51 the resistance value at its potentiometer is changed, so that the circuit shown in FIG. 6 causes the adjustment of the lighting device 2 in the manner shown in FIG. 2.

It is apparent that the illuminating device 2 will be adjusted by the device of the present invention to correspond to any possible position of the patient. In addition to controlling the angle of inclination with which the patient sits or lies on the chair and the location of patients mouth relatively to the seat, the device of the present invention makes it possible to take into consid eration the height of the chairs seat. This takes place by the telescopic rod 42. When the seat 4 sinks while the back 5 and the mouth of the patient remain in the same positions, the rod 46 and thus the piston rod 48 will be raised. With this rising movement the guide rod with the resistance 51 is also raised. If the setting is otherwise the same the slider moves somewhat to the right and the slider 59 engages a somewhat larger angle a at the resistance segment 60. In accordance with the circuit shown in FIG. 6 the changes in resistance cause a shifting of the illuminating device 2 in such manner that the light spot of the two lights 9 and 10 will be always directed to the treating location, namely the mouth of the patient.

FIG. 6 illustrates the electrical circuit of the device. The two resistances 51 and located in the casing 41 of the control device 40 attached to the chair, and the two corresponding resistances 27 and 29 carried by the rail 12 and the carriage 11, are interconnected in the manner of a Wheatstone bridge. The left hand part of the circuit is concerned with the longitudinal movement of the carriage 11 along the rails 12 and 13 (FIGS. 1 and 2), and includes the motor 22 with its exciter winding 62, a differential amplifier 63, two amplifiers 64 and 65, relays 66 and 67 with corresponding pairs of contacts 68 and 69, as well as fixed resistances 70 to 73. The right hand part of the circuit is concerned with the swinging of the arm 8 about the axis 14. Parts in the right hand side of FIG. 6 which correspond to those on the left hand side are indicated by reference numerals 74 to 85.

It is apparent from the left hand side of the circuit that the slider 28 is connected by the resistance 71 with one inlet of the differential amplifier 63, while the slider 55 is connected by the resistance 72 with the other inlet, while the outlet of the amplifier 63 is connected with the inlets of amplifiers 64 and 65. If the voltage potential at the inlets of the amplifier 63 is not the same, namely positive or negative. then depending upon the type of the potential either the relay 66 or the relay 67 is attracted and the motor 22 is switched on by contacts 68 or 69 for rotation in one or the other direction. The carriage 11 is shifted in one direction until the Wheatstone bridge is balanced, namely, when the resistances 27 and 51 are the same, until the partial resistances in the two voltage dividers 27 and 51 are balanced. Then the amplifier 63 does not receive a signal any more, the attracted relay 66 (or 67) drops and the motor 22 receives no more voltage and is switched off. In the circuit illustrated in FIG. 6 the voltage difference is between the two resistances 28 and 51, so that the relay 66 is attracted.

The motors 22 and 23 are supplied with direct current. In FIG. 6 their supply voltage is indicated as U 1 and the feed voltage for both electrical switching elements as U The amplifiers 64, 65 as well as 76, 77 are used to actuate the relays 66, 67 and 78, 79 only in case of a corresponding value.

The same applies to the function of the right hand portion of the circuit of FIG. 6.

Instead of the magnifying stages 63, 64 65 or 75, 76, 77 and relays 66, 67 or 78, 79 connected with each actuating motor, it is possible to use polarized relays each of which would switch the motor in the one or the other direction depending as to whether the applied voltage is positive or negative.

I claim:

1. A device for adjusting a dental illumination apparatus relatively to an adjustable dental treating chair, comprising shifting means for varying the direction of light rays of said illumination apparatus, a control device for said shifting means, said control device comprising an actual value transmitter connected with said illumination apparatus and producing an actual value corresponding to the actual direction of light rays, a nominal value transmitter connected with said chair and producing a nominal value corresponding to the position of said chair, and means connected with the actual value transmitter and the nominal value transmitter for comparing and adjusting said actual values to the nominal values, whereby for a preselected nominal value and when the actual and nominal values are equal said light rays are directed to a part of said chair corresponding to the mouth of a seated patient.

2. A device in accordance with claim 1, wherein said chair having a part (4) which is adjustable in its height and wherein the nominal value transmitter comprises a mechanical probe (40) connected with the height adjustable part (4) to feel by touch the height of said part with regard to the floor.

3. A device in accordance with claim 2, wherein said chair having a seat part (4) and a back part (5), said probe (40) being connected with the seat part and the back part for feeling by touch the location of the seat part with regard to the floor and the inclination of the back part with regard to the seat.

4. A device in accordance with claim 1, wherein said control device consists of an electrical follow-up control device.

5. A device for adjusting a dental illumination apparatus relatively to an adjustable dental treating chair, comprising shifting means for varying the direction of light rays of said illumination apparatus, a control device for said shifting means, said control device comprising an actual value transmitter connected with said illumination apparatus and producing an actual value corresponding to the actual direction of light rays, a nominal value transmitter connected with said chair and producing a nominal value corresponding to the position of said chair, and means connected with the actual value transmitter and the nominal value transmitter for comparing and adjusting said actual values to the nominal values, whereby for a preselected nominal value and when the actual and nominal values are equal said light rays are directed to a part of said chair corresponding to the mouth of a seated patient, wherein said control device consists of an electrical follow-up control device, an immovable part, wherein said probe device (40) includes a substantially vertical telescopic rod (42) having one end (46) engaging said immovable part and another end connected with the heightadjusting means, a potentiometer with variable contact and means connected with both ends of the telescopic rod and varying the resistance of said potentiometer when the length of said telescopic rod is varied.

6. A device in accordance with claim 5, comprising a vertically guided transmitting member (48) connected with the longitudinally movable part of said telescopic rod (41), said potentiometer having a horizontal resistance length (51) being connected with said transmitting member (48), a guiding member, (54) and a slider, (55) said guiding member being connected with said slider for moving said slider upon said vertical resistance length (51).

7. A device in accordance with claim 6, wherein said probe device comprises a setting member (43,57) connected with said height adjustable parts (4,5) and swingable with the chair back, and a pivoted rod (56) connecting said setting member with the guiding member (54) of said potentiometer.

8. A device in accordance with claim 7, having a further potentiometer (59,60), said setting member is carried by the chair back and has an extensible portion (43) connected with said pivoted (56) rod, the last mentioned potentiometer having a slider and used for determining the chair back inclination, the lastmentioned slider being connected with said pivoted rod (56), the last-mentioned potentiometer having a resistance length (60) angularly firmly connected with said guiding member (54) of the first mentioned potentiometer.

9. A device in accordance with claim 5, wherein said illumination apparatus comprises a swingable supporting arm (8) and two spaced lights (9,10) carried by said supporting arm, a carriage (11) carrying said arm, a rail (12,13) carrying said carriage and a motor driving said carriage upon said rail along a horizontal axis, the means producing the required value comprising two members, one of which follows the height of the chair while the other follows the inclination of the chair back, the means producing the actual value comprising two members corresponding to the two firstmemtioned. means, one of the two last-mentioned members follows the location of said carriage and the other one of the two last-mentioned members follows the position of said supporting arm. 

1. A device for adjusting a dental illumination apparatus relatively to an adjustable dental treating chair, comprising shifting means for varying the direction of light rays of said illumination apparatus, a control device for said shifting means, said control device comprising an actual value transmitter connected with said illumination apparatus and producing an actual value corresponding to the actual direction of light rays, a nominal value transmitter connected with said chair and producing a nominal value corresponding to the position of said chair, and means connected with the actual value transmitter and the nominal value transmitter for comparing and adjusting said actual values to the nominal values, whereby for a preselected nominal value and when the actual and nominal values are equal said light rays are directed to a part of said chair corresponding to the mouth of a seated patient.
 2. A device in accordance with claim 1, wherein said chair having a part (4) which is adjustable in its height and wherein the nominal value transmitter comprises a mechanical probe (40) connected with the height adjustable part (4) to feel by touch the height of said part with regard to the floor.
 3. A device in accordance with claim 2, wherein said chair having a seat part (4) and a back part (5), said probe (40) being connected with the seat part and the back part for feeling by touch the location of the seat part with regard to the floor and the inclination of the back part with regard to the seat.
 4. A device in accordance with claim 1, wherein said control device consists of an electrical follow-up control device.
 5. A device for adjusting a dental illumination apparatus relatively to an adjustable dental treating chair, comprising shifting means for varying the direction of light rays of said illumination apparatus, a control device for said shifting means, said control device comprising an actual value transmitter connected with said illumination apparatus and producing an actual value corresponding to the actual direction of light rays, a nominal value transmitter connected with said chair and producing a nominal value corresponding to the position of said chair, and means connected with the actual value transmitter and the nominal value transmitter for comparing and adjusting said actual values to the nominal values, whereby for a preselected nominal value and when the actual and nominal values are equal said light rays are directed to a part of said chair corresponding to the mouth of a seated patient, wherein said control device consists of an electrical follow-up control device, an immovable part, wherein said probe device (40) includes a substantially vertical telescopic rod (42) having one end (46) engaging said immovable part and another end connected with the height-adjusting means, a potentiometer with variable contact and means connected with both ends of the telescopic rod Nd varying the resistance of said potentiometer when the length of said telescopic rod is varied.
 6. A device in accordance with claim 5, comprising a vertically guided transmitting member (48) connected with the longitudinally movable part of said telescopic rod (41), said potentiometer having a horizontal resistance length (51) being connected with said transmitting member (48), a guiding member, (54) and a slider, (55) said guiding member being connected with said slider for moving said slider upon said vertical resistance length (51).
 7. A device in accordance with claim 6, wherein said probe device comprises a setting member (43,57) connected with said height adjustable parts (4,5) and swingable with the chair back, and a pivoted rod (56) connecting said setting member with the guiding member (54) of said potentiometer.
 8. A device in accordance with claim 7, having a further potentiometer (59,60), said setting member is carried by the chair back and has an extensible portion (43) connected with said pivoted (56) rod, the last mentioned potentiometer having a slider and used for determining the chair back inclination, the last-mentioned slider being connected with said pivoted rod (56), the last-mentioned potentiometer having a resistance length (60) angularly firmly connected with said guiding member (54) of the first mentioned potentiometer.
 9. A device in accordance with claim 5, wherein said illumination apparatus comprises a swingable supporting arm (8) and two spaced lights (9,10) carried by said supporting arm, a carriage (11) carrying said arm, a rail (12,13) carrying said carriage and a motor driving said carriage upon said rail along a horizontal axis, the means producing the required value comprising two members, one of which follows the height of the chair while the other follows the inclination of the chair back, the means producing the actual value comprising two members corresponding to the two first-memtioned means, one of the two last-mentioned members follows the location of said carriage and the other one of the two last-mentioned members follows the position of said supporting arm. 